Open Cascade中的布尔操作

Open Cascade中的布尔操作

Modeling Algorithms Boolean Operations

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布尔操作（Boolean Operations）是通过两个形状（S1，S2）的组合来生成新的形状。布尔操作有如下几种类型：

u 并集操作Fusion：Gets all the points in S1 or S2;

u 交集操作Common：Gets all the points in S1 and S2;

u 差集操作Cut S1 by S2：Gets all the points in S1 and not in S2;

下图所示为三种布尔操作：

1. BRepAlgoAPI_BooleanOperation

类BRepAlgoAPI_BooleanOperation是布尔操作的基类。

2. BRepAlgoAPI_Fuse

类BRepAlgoAPI_Fuse执行布尔并集操作。如下所示：

TopoDS_Shape theBox1 = BRepPrimAPI_MakeBox(50,200,70); 

TopoDS_Shape theBox2 = BRepPrimAPI_MakeBox(-30,150,70); 

TopoDS_Shape FusedShape = BRepAlgoAPI_Fuse(theBox1,theBox2); 

Fuse two boxes

3. BRepAlgoAPI_Common

类BRepAlgoAPI_Common执行布尔交集操作，如下所示：

gp_Ax2 axe(gp_Pnt(10,10,10),gp_Dir(1,2,1)); 

TopoDS_Shape theBox = BRepPrimAPI_MakeBox(axe,60,80,100); 

TopoDS_Shape theWedge = BRepPrimAPI_MakeWedge(60.,100.,80.,20.); 

TopoDS_Shape theCommonSurface = BRepAlgoAPI_Common(theBox,theWedge); 

Compute the common surface

4. BRepAlgoAPI_Cut

类BRepAlgoAPI_Cut执行布尔差集操作，如下所示：

TopoDS_Shape theBox = BRepPrimAPI_MakeBox(200,40,40); 

TopoDS_Shape theSphere = BRepPrimAPI_MakeSphere(gp_Pnt(100,20,20),80); 

TopoDS_Shape ShapeCut = BRepAlgoAPI_Cut(theSphere,theBox); 

5. BRepAlgoAPI_Section